1. Field of the Invention
This invention relates to missile control or other vehicle control technology, more particularly to a missile with a lightweight pneumatic pilot valve for controlling a main valve generally via diversion of propellant thrust.
2. Description of the Related Art
Self-propelled vehicles, including missiles and the like, are generally propelled by a main engine exerting thrust rearwardly to propel the missile through a medium, such as air. The same can be said for underwater missile technology, as well as torpedoes. The use of a single engine generally means that the rearward thrust is precisely aligned with the vehicle's center of gravity. Use of a single main engine generally does not allow for the lateral control of the missile with that engine, especially in solid fuel applications. As used herein, the term “missile” is used to indicate any propelled craft subject to the consideration and constraint as indicated by context.
One way to laterally control a missile is to use side thrusters to control the roll, pitch, and yaw, movements of the missile. These side thrusters can be powered by the same engine propellant as the main rearward-thrust engine. In this arrangement, valves are used to thrust laterally so that the missile can be maneuvered. The greater the precision of the thrust application both rearwardly and laterally, the greater the accuracy of the missile. Such accuracy is of great advantage with respect to both military and possibly civilian applications.
Missile technology can be used to deliver a weapons payload for military purposes or a civilian payload for other purposes, such as to quickly deliver rescue materials to isolated locations. Missiles can deliver such payloads very rapidly and very accurately with the proper attitude control.
Pneumatic pilot valves can be used for control of the main lateral thrust valves to provide means by which these lateral thrust valves can be operated. High temperature divert and attitude control valves for missiles and spacecraft can use one or more pilot stages to achieve fast response in high mass flow valves. In certain applications, such as solid fueled rockets and missiles, pilot valves usually have small flow passages and elements that are sensitive to erosion and contamination from condensables arising from the hot gases produced by the solid propellant gas generators. In order to resolve the demands for better missile and craft technology, the present invention provides a better solution to the demand and need for missile pilot valves such as those that control lateral thrusting.
In addition to the difficulties posed by valves, solid fuel missiles in general with diameters of less than roughly 30 inches have had to depend upon fins to guide the missile. Larger missiles and rockets have used thrust diversion valves in place of fins for guidance. However, conventional thrust valves are of the size and weight that would make them impractical to use for guidance in place of fins on such smaller vehicles having solid fuel and associated high temperature operating environments. This is especially so in the area of solid fueled tactical missiles, which may have a diameter of 10 inches or less.
In view of the foregoing, a need exists for a cost effective, lightweight, pneumatic pilot valve capable of withstanding the corrosive, erosive, and other effects of hot gases produced from solid propellant gas generators. Additionally, there is also a need for a main lateral thrust control valve that sufficiently seals the lateral thrust nozzle when off or inactive yet is able to operate quickly and reliably when needed. The present invention satisfies one of more of these needs.